TWO-COMPONENT POLYURETHANE COATING COMPOSITIONS

摘要

Two-component coating compositions, methods for their preparation and use are disclosed. The two-component coating compositions include an isocyanate-functional component and an isocyanate-reactive component comprising a hydroxyl-functional polymer. The isocyanate-functional component includes: (a) an aliphatic polyisocyanate containing allophanate structural units; and (b) a cycloaliphatic polyisocyanate comprising an allophanate group and an isocyanurate trimer group.

主权项

1. A two-component coating composition comprising:
(1) an isocyanate-functional component, and (2) an isocyanate-reactive component comprising a hydroxyl-functional acrylic polymer and/or a hydroxyl-functional polyester, wherein the isocyanate-functional component comprises:
(a) an aliphatic polyisocyanate containing allophanate structural units and having the structure:in which: (i) Q1 and Q2 independently of one another are the radical of an aliphatic diisocyanate, (ii) R1 and R2 independently of one another are hydrogen or a C1-C4 alkyl radical, (iii) Y is the radical of a starter molecule with a functionality of from 2 to 6, (iv) n is a number from 2 to 6, and (v) m corresponds to a number of monomer units such that the number-average molecular weight of the polyether on which the structure is based is 300 to 20,000 g/mol; and
(b) a cycloaliphatic polyisocyanate comprising an allophanate group and an isocyanurate trimer group.